An object of U.S. Patent Application Publication No. 2013/0204477 (referred to as “US 2013/0204477 A1” below) is to, in the event of a collision, promptly discharge electric charge stored in a smoothing capacitor while further appropriately protecting an inverter and a three-phase alternating current motor ([0006] and Abstract). To achieve the object, in US 2013/0204477 A1, after a collision has been detected, all the upper arm transistors T11 to T13, T21 to T23 of inverters 41, 42 are turned off, and all the lower arm transistors T14 to T16, T24 to T26 are turned on. Then, when no counter-electromotive force is generated in motors MG1, MG2, a gate voltage V2 lower than a gate voltage V1 at which each upper arm transistor completely turn on is applied to at least one of the upper arm transistors T11 to T13, T21 to T23 of the inverters 41, 42. In addition, among the lower arm transistors T14 to T16, T24 to T26 of the inverters 41, 42, lower arm transistors that are connected in series with the upper arm transistor to which the gate voltage V2 is applied is turned on (Abstract).
An object of Japanese Laid-Open Patent Publication No. 2011-182578 (referred to as “JP 2011-182578 A” below) is to provide a power converting device that can realize overheat protection and discharge electric charge of a capacitor ([0004] and Abstract). To achieve the object, JP 2011-182578 A discloses that a temperature sensor 27 detects a temperature of a lower arm transistor 24. A control circuit 26 simultaneously turns on an upper arm transistor 23 and the lower arm transistor 24 while imposing a current limit on the lower arm transistor 24, and then electric charge of a high voltage capacitor 25 is discharged via the transistors 23, 24. In addition, when the temperature of the lower arm transistor 24 detected by the temperature sensor 27 reaches a specified value, the control circuit 26 turns off the lower arm transistor 24 (Abstract).